Suturing may be a very time-consuming phase of certain surgical operations, such as those involving sensitive or delicate tissue. Heretofore it has been realized that the suturing phase of many surgical operations may be shortened considerably by the use of suitable stapling devices. As a consequence a number of different types of surgical stapling devices have come into use. Some of the developments in surgical stapling devices are illustrated by U.S. Pat. Nos. 3,604,561, 3,646,801, 4,162,678, 4,316,468, 4,317,451 and 4,485,816, and the references cited therein.
However, prior surgical stapling systems suffer from one or more disadvantages, such as but not limited to: (1) excessive size of the stapler and/or staples for the intended use; (2) the need to bend the staples around an anvil as they are being implanted, which tends to induce severe traumatic effects in the tissue being sutured stemming from the need to extract the anvil from the tissue surface each time a staple has been implanted; and (3) inability to maintain precise edge alignment and smoothness as required in ophthalmic and cosmetic surgery. As a consequence, prior medical staplers have been unsuitable for uses such as delicate ophthalmic surgery where only an absolute minimum of trauma induced during the surgical procedure may be tolerated.
In an effort to avoid those or other limitations, a stapling system has been designed which consists of a stapler head that comprises (1) a staple magazine formed from a stainless steel sheet and consisting of a plurality of identical staples attached to and supported by a plurality of integral frame members, (2) means defining a staple ejection slot or aperture, (3) means for supporting the staple magazine, (4) means for advancing the staple magazine so that its leading staple is located in a predetermined dispensing position in proximity to the staple ejection slot, and (5) staple driving means having a reciprocal ram plate for severing the leading staple and driving it through the ejection slot so as to implant it into tissue engaged by the stapler head. The stapler head has no anvil, but instead the ram plate and staples are so shaped that when the ram plate is driven through its work stroke in driving engagement with the leading staple, the ram plate causes the shape of the leading staple to be transformed as it is being implanted, so that the two legs of the staple penetrate the tissue via an arc of trajectory that closely resembles the motion of a surgeon's suturing needle. The stapler head is adapted to be attached to a suitable driver which provides the force required to cause the ram plate to implant the leading staple into tissue. Such an improved stapler system is disclosed in a copending U.S. patent application filed by William D. Richards, Ernesto E. Blanco, Richard A. Clark and John C. Meade for SURGICAL MICROSTAPLER U.S. Pat. No. 217,554.
One of the major requirements of a driver suitable for use with the stapler head described in said copending U.S. patent application of William D. Richards, Ernesto E. Blanco, Richard A. Clark and John C. Meade is that it must be capable of causing the ram plate to drive the staples with a velocity which exceeds the ability of live tissue to react dynamically under the force of a penetrating staple, so as to make it unnecessary to hold the limp edges of some delicate tissues at the time of stapling. A further primary requirement is that the driver be small enough to be easily grasped and manipulated by the surgeon's hand. Another requirement is that the driver be low in weight so as to facilitate placing the stapler head in light contact with the tissue to be sutured, and also to increase operator control and lessen operator fatigue. A further requirement is that the driver be easily attached to and detached from the stapling head, so as to permit substitution of a new full stapler head when the staple head currently in use has been exhausted of staples. It also is desirable, though not essential, that the driver be manually powered, so as to eliminate the need for any electrical, hydraulic or pneumatic power cables.
Accordingly the primary object of this invention is to provide a driver for a surgical microstapler that meets the foregoing requirements.
A further object is to provide a driver that has a relatively simple construction yet provides a precise driving action on operator command.
Still other objects and advantages will be obvious to persons skilled in the art from the following detailed description which is to be considered together with the accompanying drawings.